Rung for a ladder and method of making the same



Nov. 11, 1969 HOPFELD RUNG FOR A LADDER AND METHOD OF MAKING THE SAMEFiled Feb. 15, 1968 2 Sheets-Sheet 1 HENRY HOPFELD ATTORNEY H. HOPFELDNbv. 11, 1969 RUNG FOR A LADDER AND METHOD OF MAKING THE SAME Filed Feb.15, 1968 2 Sheets-Sheet 2 4 INVENTOR HEN/7) HOPFELD ATTORNEY UnitedStates Patent RUNG FOR A LADDER AND METHOD OF I MAKING THE SAME HenryHopfeld, Ross, Calif. (732 A St, San Rafael, Calif. 90701) Filed Feb.15, 1968, Ser. No. 709,169 Int. Cl. E06c 7/08 US. Cl. 182-228 2 ClaimsABSTRACT OF THE DISCLOSURE A generally cylindrical metal rung which hasfour diametrically opposite longitudinal ribs; two of the ribs deliningthe top of the rung and are bent outwardly away :from one another. Thespace between the top ribs is the stepand has a plurality oflongitudinal grooves and at least a middle portion is serrated anddented in such fashion as to lock the material which forms thefrictional step surface on the rung; this frictional step surface isformed as follows: epoxy is applied to the serrated middle portion ofthe top of the rung so as to substantially fill the space between thetop ribs, then a layer of grit is placed upon and pressed into the epoxyand baked, and while still hot another layer of epoxy is spread on thegrip surface so as to solidify and integrate the friction layer on therung; the extreme ends of the rung are provided with spaced teeth andpressed into a hole in the respective rails of the ladder, the holecontaining epoxy so that the epoxy flows around the toothed end portionof the rung and also into the end of the rung to cushion and bind therung in place.

BRIEF DESCRIPTION OF THE INVENTION The invention is to obviate thepeeling off of the friction surface from the top of such rung and alsoeliminates the disadvantage of the grip surface projecting to theexposed edges of the rung and catching the trousers or scratching thelegs of the user; such disadvantages are eliminated by the method stepswhereby the epoxy and the grit are integrated into the serrations on thestep portion of the rung; and confined between the top ribs whichpresent protective rounded edges for contact, the rung being held fromturning or becoming loose by a plurality of teeth on its end so directedas to bite into the walls of the hole in the respective rails of theladder and by the provision of the binding and cushioning packing ofepoxy in said holes of the rails.

DESCRIPTION OF FIGURES.

FIG. 1 is a fragmental plan view of the rung.

FIG. 2 is a fragmental sectional view of the rung in the ladder.

FIG. 3 is a side view of rungs in an extension'ladder hooked forextended position.

FIG. 4 is a cross-sectional view of a rung before the friction filler isapplied.

FIG. 5 is a sectional view of the rung with friction filler.

DETAILED DESCRIPTION The rung is made of a cylindrical tubular body 1,the ends 2 of which fit into holes 3 in the opposite rails of a latter.

There are four diametrically opposite longitudinal ribs projecting fromthe outer periphery of the body 1, which are so located that a pair offlange ribs 6 project outwardly and define the top or step surface ofthe rung and another pair of ribs 7 project downwardly and somewhatoutwardly from the periphery of the body 1. These ribs 6 and 7 formabutments when the ladder is manipulated at any incline, so that lateralimpact or stress is exerted on the ribs which reinforce the rung body 1.

A friction surface is produced in the space 8 between the top flangeribs 6 by the following steps: the surface of the body between theflange ribs 6 is grooved longitudinally and somewhat flattened andindented transversely to form locking pockets 9 generally in the mannerofserrations; a binder, such as epoxy, is spread between the flange ribs6 filling the space 8 to about the edges of the flange ribs 6; suitablegrit is spread on the epoxy so as to penetrate into the epoxy, and thefiller is baked to a suitable hard consistency; then while the filler isstill hot another layer of epoxy is spread over the grit so as to setand harden and form the step surface on the rung.

The edges 11 of the flange ribs 6 are rounded and protect the user fromabrasion by the grit, and also protect the friction layer fromtransverse or lateral shearing forces thereby further to prevent theloosening or peeling of the friction surface.

Spaced from but near each end of the rung body 1 each flange rib 6 isdented to form a socket 12. When the rung is used in an extensionladder, as shown in FIG. 3, hooks 13 are used to hold the ladderextended, and the sockets 12 are located near the adjacent rails 4 tonest the respective hooks 13.

On each end 2 of the rung body 1 is provided a plurality of annularseries of teeth 14 the sharp outer ends 16 of which incline toward theopposite end so as to bite into the walls of the holes 3 and furtherresist pulling out of the hole 3.

An annular groove 17 is formed in the bottom 18 of each hole 3conforming to the extreme end of the tubular body 1. Epoxy placed intothe hole 3 flows around the outer periphery of the end 2 and is alsotrapped into a plug 19 on the bottom 18 of the hole 3 so as to bind andcushion both the inside and outside of the tubular end 2. a

The method and rung herein obviates the tearing off or peeling thefriction surface from the top of the rung, it protects the user, it alsoprotects the step surface, prevents loosening of the rung, and generallyprolongs the utility of the ladder.

I claim:

1. A rung for securing in the rails of ladders comprismg (a) a generallycylindrical body,

(b) at least a pair of parallel longitudinal ribs spaced apart to definea step surface on the top of the body,

(c) friction means confined between said ribs and substantially fillingsaid space and being bound to said body and to said ribs, whereby saidribs protect the respective edges of said friction means,

(d) said rails having holes for the ends of said rungs,

(e) said body being tubular metal,

(f) a plurality of annular series of teeth projecting from the peripheryof each end of said body and being fitted into said holes in therespective rails and being adapted to bite into the walls of therespective holes,

(g) each of said holes having an annular pocket to receive the extremeend of said tubular body and containing a binder to form cushioningsecuring means around said teeth and inside the end of said body.

2. A rung for securing in the rails of ladders compris- (a) a generallycylindrical body,

(b) at least a pair of parallel longitudinal ribs spaced apart to definea step surface on the top of the body,

(c) friction means confined between said ribs and substantially fillingsaid space and being bound to said References Cited body and to saidribs, whereby said ribs protect the N T STATES PATENTS respective edgesof said friction means, 2,895,389 7/1959 Nagin 52 180 (d) said ribsprojecting respectively outwardly from 3,042,140 7/1962 Basile 182 46said body thereby to form abutments on said rung, 5 3,369, 30 2 19 i 1 2223 (eiozfigglziiigbemg an extenslon ladder and havlng FOREIGN PATENTS(f) said ribs being dented spaced from but near each 941,531 9/1963Great Britain' end thereby to form sockets adjacent each rail for 102/1967 Frange' engagement with said locking hooks. REINALDO P. MACHADO,Primary Examiner

